This invention relates generally to fluid pumps, and more particularly, to a protection system for preventing failure of flywheels due to a pump overspeed condition.
The use of flywheels for energy storage with pumps and motors is widespread. The flywheel typically is directly coupled to the drive shaft of the motor and the pump, and rotates therewith. The use of the flywheels, though, has problems associated therewith. For example, in the event the main pump loses coolant to be pumped, the drive shaft will increase its speed of rotation. This increased rotation speed of the drive shaft likewise increases the speed of rotation of the flywheel. Under some circumstances, the increase in speed of the drive shaft and the flywheel, or overspeed, can cause catastrophic failure of the flywheel. One such accident may be that the flywheel will literally explode off the drive shaft, thereby creating a potentially hazardous environment for operating personnel and contiguous equipment.
Numerous devices have been devised which attempt to prevent flywheel failure. Some of these devices are, for example, regenerative electrical braking and mechanical braking systems. However, these devices have disadvantages in that they are either complex, expensive, potentially unreliable, or require complex sensing devices and/or human intervention.